Why can dinosaurs escape the extinction of the tri -stacks?Jiangsu experts infer that dinosaurs have feathers with warmth function

The intersection news has a dinosaur with a strong four limbs, a huge body, or walking on the coast plain, or walking in the original jungle ... When the dinosaurs are mentioned, people's first reaction is "Earth Outlord". But the dinosaurs were not the "earth hegemon" at the beginning. At the end of the three stacks, a large number of land and marine life disappeared from a biological extinction incident, but dinosaurs escaped the disaster. After that, the dinosaurs quickly occupied the ecological position, dominating the world of Jurassic and the Baiji. Why do large amounts of land organisms extinct at the end of the three stacks? Why can dinosaurs survive in the natural disaster of biostatic and develop rapidly after the disaster?

Recently, research by the Nanjing Institute of Geology, the Institute of Geology, the Chinese Academy of Sciences (referred to as the "South Ancient Institute") cooperated with Professor Paul Olsen of Columbia University Paul Olsen in the United States and others. The main reason for the extermination of land biological extinction at the end of the Tri -stack, and the dinosaurs have already adapted to the cold climate of the polar ground, and have a feathers with warm -keeping function. In the end, they can escape the hostel and occupy the main position of Jurassic ecology in winter.

The polar regions can be frozen during the greenhouse, and the dinosaurs are distributed in the middle and high latitudes

The concentration of the atmospheric carbon dioxide, the earth's poles have no glaciers, and the forest coverage to the north and south poles of Panjia continent ... The earth existed in a typical greenhouse in the early days to the early Jurassic world.

"For the first time, we found ice rafts in the Junggar Basin to find ice rafts from the dwarf -in -early Jurassic Lake." Fang Yaman introduced that the ice raft deposits, that is, the lake and ice are transported to the center of the lake like a bamboo raft like a bamboo raft. In the end, the gravel was deposited at the bottom of the lake. The research team re -corrected the ancient latitude of the Junggar Basin and believed that it was located in the North Pole of Panjia. In other words, even during the greenhouse and globe of the two poles without glaciers, seasonal frozen has the temperature, and the temperature can reach zero.

In addition to the discovery of ice raft deposits, the research team also found the exquisitely preserved dinosaur footprint fossils at the same time. The discovery shows that in the evening of the three stacks to the early Jurassic world, dinosaurs lived in polar regions and adapted to polar seasonal cold climate.

The distribution of plants also proves the season with seasonal severity. The equatorial area is dominated by pine and cypress, seed ferns, and ferns; the subtropical region is mainly pine and cypress, with low diversity; medium and high latitudes regions have high diversity. Big leaves, pine cypress, ginkgo and trees with obvious growth patterns.

"Before the end of the three stacks, the distribution of dinosaurs had obvious latitudes: dinosaurs, especially herbivorous dinosaurs, mainly distributed in medium and high latitudes." Sha Jingeng added. Although carnivorous dinosaurs also exist in low latitudes, the number is very small.

The volcanic winter causes biological extinction, and dinosaurs resist the cold winter with feathers

For a long time, it is believed that the global warming, ocean acidification and hypoxia caused by the eruption of the central Atlantic superflinter province have led to extinction of marine life. However, the research team believes that if the global heating up, land organisms will be migrated from low latitudes to high latitude. The class is extinct.

"Therefore, we infer that the" cold 'of volcanic winter "has caused the great extinction of land biology, not the" hot "that is considered by the traditional point of view." Sha Jin Geng introduced that the large number of volcanic ash and air -solid oscillating of the super volcanic eruption block The surface temperature drops sharply, this is "volcanic winter". However, its duration is generally in several years to decades, and it is difficult to record directly in the sediment.

The research team also inferred that dinosaurs were born with feathers, but these feathers were not used to fly. "But large sauropus dinosaurs have not found fossils with feathers," Sha Jin Geng explained. "Large dinosaurs may need heat dissipation instead of insulation, but they may have feathers when they are born, but the feathers have returned when they grow up. . Just as an African elephant has no hair, but the small elephant is hairy. "

Studies believe that these primitive feathers are the most likely to use in warmth. In the medium and high latitudes, there are no predators without feather insulation, and dinosaurs have feathers that can keep insulation to resist the winter, and then exclusively enjoy rich and stable plant resources.

Biostatic extinction, the rise of dinosaur ecology

"The ice raft sedimentation and dinosaur footprint fossil records can directly prove that the dinosaurs with feather insulation have adapted to the seasonal cold climate since the first time in the evening." Fang Yaman said that this has helped them success. The volcanic winter caused by the eruption of the central Atlantic super volcano at the end of the tri -stack. Other animals without feather insulation are extinct in volcanic winter. Only a few small types of small volumes hide in the cave and escape the disaster.

After the biological extinction incident, the volume of dinosaurs increased rapidly and the distribution range expanded rapidly. Dinosaurs expanded from middle and high latitudes to low latitudes, bird hip dinosaurs appeared for the first time, and the volume of beast -footed dinosaurs increased by nearly 20%, while the total number of dinosaurs was nearly doubled. Since then, dinosaurs have opened the era of earth -land hegemony for 130 million years.

But since the dinosaurs have survived the volcanic winter at the end of the tri -stack at the end of the three stacked feathers.Fang Yaman speculated that this was because the volcanic winter was too large in winter caused by the impact of Baiji Ji Xingxing, and the plants died in large areas; as the weight and volume increased, the food demand of dinosaurs became larger.Under complex factors such as food shortage and volcanic winter, dinosaurs eventually extinct.Xinhua Daily · Jiaojiao Reporter Zhang Xuan

Intern Sun Guangzhe

Picture Source South Ancient Institute

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